As seen on Astronomy Picture of the Day Orion rises over El Castillo, the central pyramid at Chichén Itzá, one of the great Mayan centers on the Yucatán peninsula. Also known as the Temple of Kukulkan it stands 30 meters tall and 55 meters wide at the base. Built up as a series of square terraces by the pre-Columbian civilization between the 9th and 12th century, the structure can be used as a calendar and is noted for astronomical alignments. In fact, the Mayans were accomplished astronomers and mathematicians, accurately using the cyclic motions of the stars, Sun, Moon, and planets to measure time and construct calendars. In the Mayan era, the celestial equator, nowadays passing close to Orion belt, was located towards the northern part of the constellation. It is accepted that the Orion constellation was represented as a turtle, and is also called the "heart of heaven". The fusion of Mayan construction techniques with new elements from central Mexico make Chichen-Itza one of the most important examples of the Mayan civilization in Yucatán. In 1988 it was declared a UNESCO World Heritage Site. See a larger image and more information on Stéphane Guisard page: sguisard.astrosurf.com/Pagim/Chichen-Itza.html